Bulletin of the Natural History Museum (Formerly: Bulletin of the British Museum

"STORY MUSEUf Bulletin of 26 NOV 1997 The Natural Histor Museum Botany Series THE NATURAL HISTORY MUSEUM VOLUME 27 NUMBER 2 27 NOVEMBER 1 997 The Bulletin of The Natural History Museum (formerly: Bulletin of the British Museum (Natural History) ), instituted in 1949, is issued in four scientific series, Botany, Entomology, Geology (incorporating Mineralogy) and Zoology. The Botany Series is edited in the Museum's Department of Botany Keeper of Botany: Dr S. Blackmore Editor of Bulletin: Ms M.J. Short Papers in the Bulletin are primarily the results of research carried out on the unique and ever- growing collections of the Museum, both by the scientific staff and by specialists from elsewhere who make use of the Museum's resources. Many of the papers are works of reference that will remain indispensable for years to come. All papers submitted for publication are subjected to external peer review for acceptance. A volume contains about 160 pages, made up by two numbers, published in the Spring and Autumn. Subscriptions may be placed for one or more of the series on an annual basis. Individual numbers and back numbers can be purchased and a Bulletin catalogue, by series, is available. Orders and enquiries should be sent to: Intercept Ltd. P.O. Box 7 16 Andover Hampshire SP10 1YG Telephone: (01264) 334748 Fax: (01264) 334058 Claims for non-receipt of issues of the Bulletin will be met free of charge if received by the Publisher within 6 months for the UK, and 9 months for the rest of the world. World List abbreviation: Bull. nat. Hist. Mus. Lond. (Bot.) The Natural History Museum, 1997 Botany Series ISSN 0968-0446 Vol. 27, No. 2, pp. 77-147 The Natural History Museum Cromwell Road London SW7 5BD Issued 27 November 1997 Typeset by Ann Buchan (Typesetters), Middlesex Printed in Great Britain by Henry Ling Ltd., at the Dorset Press, Dorchester, Dorset Bull. not. Hist. Mus. Loncl. (Bot.) 27(2): 77-147 Issued 27 November 1997 Systematics of Pogostemon (Labiatae) 78 G.R. BHATTI AND M. INGROUILLE included three D. D. maintained as operational taxonomic units as a first step in a revision Dysophylla species: auricularia, myosuroides and D. Benth. In the same work Bentham of the infrageneric classification. Benth., strigosa (1832- divided the into two the Non-patchouli species of Pogostemon sensu stricto are more 1836) genus Pogostemon sections, basis of the of inflores- diverse and better delineated. For example there is P. litigiosus Doan Paniculatae and the Racemosae on the type with a two-lipped calyx. Species are generally narrowly endemic to cence. was taken areas such as Sri Lanka or southern India, the eastern Himalayas, Bentham's splitting of Dysophylla and Pogostemon Yunnan, Java, Borneo or southern Africa. further, first by Rafinesque-Schmaltz (1847) and later by Briquet raised Dysophylla includes all the small flowered species which tend to (1897). Rafinesque-Schmaltz (1847) effectively Dysophylla have flowers crowded into dense verticillasters. Many species have section Verticillatae to generic rank by publishing a new genus and M. a weak stem, probably because they are aquatic or marshland Eusteralis Raf, which included Mentha pumila Graham subdivided and inhabitants. The calyx is small, translucent, and infundibular with a verticillata Roxb. Briquet (1897) Dysophylla follows: wide diameter. Most species have verticillate, linear to linear- Pogostemon into sections and subsections, as lanceolate leaves. However, there are a number of species which Genus Dysophylla combine the character states of Pogostemon sensu stricto and Sect. l.Rhabdocalicinae Briq. (Calyx tube cylindrical and rounded Dysophylla, so that the boundary between these taxa has not always or very indistinct, pentagonal) been stable, with different workers putting the same species into one 1. Oppositifoliae Benth. or other group or not recognising the groups at all. This is described A. Perennial species in greater detail below. B. Annual species The study reported here is a re-examination of the variation of 2. Verticillatae Benth. Pogostemon sensu lato leading to the erection of a new infrageneric Sect. II. Goniocalicinae Briq. (Calyx tube prominently five- classification which is more natural and which may be used as the angled) basis for future studies at lower taxonomic rank. A cladistic and Genus Pogostemon phenetic analysis of characters has aided the resolution of new 1. Section Racemosa Benth. infrageneric taxa but this has not been used directly because certain A. Glabriuscula Briq. (Naked filaments) characters, thought to be more constant and reliable, have been B. Barbata Briq. (Hairy filaments) weighted as more important in the classification, but all characters 2. Section Paniculata Benth. were weighted equally in the cladistic and phenetic analysis. The A. Interrupted verticils cladistic and phenetic analysis will be reported elsewhere. B. Continuous verticils History of the classification of Pogostemon Kudo (1927) treated Dysophylla and Pogostemon as distinct genera under subtribe Pogostemoninae. He divided Dysophylla into Pogostemon was described by Desfontaines (1815) as a distinct two sections: genus of Labiatae because of its hairy stamens: pogon is Greek for - beard and pogonostemon means 'with bearded stamen' (Steam, Section Eudysophylla stem indumentum tomentose to hirsute and 1992). The type species for the genus is P. plectranthoides Desf. leaves opposite, broad, ovate-lanceolate, margin serrulate (in- Desfontaines placed his new genus near Hyssopus L. Dysophylla cludes only D. auricularia). Blume was described as a distinct genus, related to Pogostemon by - Section Chotekia stem glabrous to pubescent and leaves verticil- having bearded stamens (Blume, 1 826). Dysophylla had been previ- late, narrow, linear to linear-lanceolate with an entire margin. ously recognized as distinct by some authors under different names. Hermann (1717) gave the polynomial Veronica hirsuta latifolia Four species which belong to Bentham's Dysophylla section Zeylanica aquatlca to a species of Dysophylla. Linnaeus (1747) Oppositifoliae (D. auricularia, D. myosuroides, D. rugosa Hook.f. listed a genus Alopecuro-veronica, a name he later cited as a andD. salicifolia Dalzell ex Hook.f.) were transferred toPogostemon synonym of Mentha auricularia (Linnaeus, 1767). The name on the basis of having opposite, broad and petiolate leaves, presence Majorana foetida was given as another synonym, a species de- of crystals in the calyx, and absence of an aerenchyma tissue in the scribed by Rumphius (1750) as Majana foetida. He described it as stem (El-Gazzar & Watson, 1967). Wu & Li (1975) also transferred having no close affinity to other species of Mentha. Blume ( 1 826) D. auricularia and D. falcata C.Y. Wu to Pogostemon but without cited Rumphius' illustration when he recognized Dysophylla as a mentioning any reason for doing so. The removal of D. auricularia, distinct genus based on Dysophylla auricularia (L.) Blume (= in particular, posed a nomenclatural problem because it is the type Mentha auricularia L.). Although he placed Dysophylla next to species ofDysophylla. A solution to this problem was put forward by Mentha L. he considered it different from Mentha by having closure Panigrahi (1976) and Bakhuizen van den Brink & van Steenis of the fruiting calyx, fleshy swelling of the disc, and bearded (1963), who suggested the generic name Eusteralis Raf. for the stamens. At about the same time Blume (1826) published a species remaining species of Dysophylla, those in section Verticillatae. from Java he called P. menthoides Blume. Later, however, Bentham Keng (1978) also placed Dysophylla section Verticillatae in (1829) questioned the placing of P. menthoides in the genus Pogostemon section Eusteralis Raf. However, Panigrahi (1984) Pogostemon because it had naked filaments. referring to Article 22.4 (I.C.B.N. 78) mentioned that Pogostemon Bentham (1829, 1830, 1832-1836) also widened the concept of section Verticillatae Benth. has priority over Pogostemon section Dysophylla by including species described as Mentha by Loureiro Eusteralis (Raf.) H. Keng. (1790) and Roxburgh (1814, 1832). Bentham (1830) divided Several authors found it difficult to distinguish Dysophylla from Dysophylla into two groups on the basis of phyllotaxy, one group Pogostemon (Hasskarl, 1842; Miquel, 1859; Kuntze, 1891; Keng, with opposite leaves and the other verticillate leaves. In Labiatarum 1978). Press (1982) criticized Briquet's division of Pogostemon and et 1 genera species Bentham ( 832) formally recognized these groups Dysophylla because of the obscurity of the characters used. Press' as section and section Verticillatae. Section 1 for the Oppositifoliae ( 982) phenetic analysis of characters found no evidence Oppositifoliae, which agreed with Blume's original description of grouping of taxa as proposed in Briquet's classification. SYSTEMATICS OF POGOSTEMON 79 MATERIALS AND METHODS for 8-12 minutes. Almost all of the samples examined were air dried, but a comparison was made with fresh material, dried using a critical point drier (POLARON) to confirm characterization. All the listed in the account specimens systematic were examined Data were subjected to cladistic analysis and phenetic analysis and used for data analysis. Some other specimens were rejected (Bhatti, 1995). Details and a comparison of the results of different because they were incomplete at the correct state of development or cladistic and phenetic analysis will be reported elsewhere. had no information about their geographical

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